System Administration Guide: Advanced Administration

System Log Rotation

System log files are rotated by the logadm command from an entry in the root crontab file. The /usr/lib/newsyslog script is no longer used.

The system log rotation is defined in the /etc/logadm.conf file. This file includes log rotation entries for processes such as syslogd. For example, one entry in the /etc/logadm.conf file specifies that the /var/log/syslog file is rotated weekly unless the file is empty. The most recent syslog file becomes syslog.0, the next most recent becomes syslog.1, and so on. Eight previous syslog log files are kept.

The /etc/logadm.conf file also contains time stamps of when the last log rotation occurred.

You can use the logadm command to customize system logging and to add additional logging in the /etc/logadm.conf file as needed.

For example, to rotate the Apache access and error logs, use the following commands:

# logadm -w /var/apache/logs/access_log -s 100m
# logadm -w /var/apache/logs/error_log -s 10m

In this example, the Apache access_log file is rotated when it reaches 100 MB in size, with a .0, .1, (and so on) suffix, keeping 10 copies of the old access_log file. The error_log is rotated when it reaches 10 MB in size with the same suffixes and number of copies as the access_log file.

The /etc/logadm.conf entries for the preceding Apache log rotation examples look similar to the following:

# cat /etc/logadm.conf
/var/apache/logs/error_log -s 10m
/var/apache/logs/access_log -s 100m

For more information, see logadm(1M).

You can use the logadm command as superuser or by assuming an equivalent role (with Log Management rights). With role-based access control (RBAC), you can grant non-root users the privilege of maintaining log files by providing access to the logadm command.

For example, add the following entry to the /etc/user_attr file to grant user andy the ability to use the logadm command:

andy::::profiles=Log Management

Or, you can set up a role for log management by using the Solaris Management Console. For more information about setting up a role, see Role-Based Access Control (Overview) in System Administration Guide: Security Services.